Extracellular YB-1 blockade in experimental nephritis upregulates Notch-3 receptor expression and signaling

Nephron Exp Nephrol. 2011;118(4):e100-8. doi: 10.1159/000324209. Epub 2011 Mar 2.


Background: Notch receptors are involved in kidney development and pathogenesis of inflammatory glomerular diseases. Given the secretion of Y-box (YB) protein-1 following cytokine stimulation and subsequent extracellular association with membrane receptor Notch-3 in vitro, we elucidated functional effects of YB-1 targeting on the Notch-3 signaling pathway.

Methods: Rat mesangial cells were challenged with a monoclonal anti-YB-1 antibody (YB-1-mAb) and analyzed for YB-1 and Notch-3 expression. Notch-3 expression in mice with a targeted disruption of one YB-1 allele (YB-1(+/d)) was compared with their wild-type littermates. Furthermore, YB-1-mAb was applied during mesangioproliferative anti-Thy1.1 nephritis, and glomerular Notch-3, Notch target genes and YB-1 expression were analyzed by immunohistochemistry, quantitative real-time PCR and immunoblotting.

Results: Upon challenge with YB-1-mAb, rat mesangial cells showed an increased expression of YB-1 and Notch-3 protein. Concordantly, we found a significant upregulation of Notch-3 expression in renal cells of YB-1(+/d) mice. YB-1-mAb treatment in anti-Thy1.1 nephritis resulted in enhanced mesangial Notch-3 expression and differential Notch target gene activation (HES2/Hey-2). Notably, YB-1 mRNA content did not differ between groups; however, glomerular YB-1 protein was significantly increased, suggesting a posttranslational mechanism.

Conclusion: Extracellular targeting of YB-1 potently induces glomerular Notch-3 receptor expression, Notch signaling and YB-1 stabilization, most likely via an autoregulatory feedback mechanism.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Animals
  • Extracellular Space / metabolism*
  • Extracellular Space / physiology
  • Gene Targeting / methods
  • Kidney Glomerulus / metabolism
  • Kidney Glomerulus / physiopathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Nephritis / metabolism*
  • Rats
  • Rats, Wistar
  • Receptor, Notch3
  • Receptors, Notch / biosynthesis*
  • Receptors, Notch / genetics
  • Receptors, Notch / physiology
  • Signal Transduction / physiology*
  • Up-Regulation / physiology*
  • Y-Box-Binding Protein 1 / antagonists & inhibitors*
  • Y-Box-Binding Protein 1 / metabolism


  • Notch3 protein, mouse
  • Receptor, Notch3
  • Receptors, Notch
  • Y-Box-Binding Protein 1